Ski bum,
I have had the same issue at my office. My cube mate came in with a cold (he's already used up all of his sick days and is on probation for it). With my immunosupressors, I got sick from it. Luckily, I was able to go on medication for it without too many CD conflicts, but it lasted for 3 weeks!! My doctor suggested wearing a "germ mask" at work, but since I have to talk on the phone, obviously, it's not the best solution in my profession. Let alone the geek factor!
I finally explained to my boss the severity of the situation with my "suppressed immune system". Although they can't force my cube mate to go home due to his attendance problems, they have tried to make allowances for me to work from home or move to another area if he's sick.
I would suggest talking to your manager just to see. As my boss said, he had no clue that "those drugs I take" would cause problems like that.
And it wouldn't hurt to talk to her either just in case she doesn't know that you have a suppressed immune system. I talked to my cube mate, and he even bought anti-viral kleenexes and disinfects his cube, etc. It's a small gesture, but he's trying to help me.
~Sway